ATBECHDEDKESFRGBGRITLILUNLSEMCPTIE..............................................R0811851EUROPEAN PATENT APPLICATIONA319980401EP97108805.919970602enenen140020/96 19960603JP19980401199814199712101997506 6G 01R 33/032 AdeFaradayrotator mit rechteckiger HystereseenFaraday rotator having a rectangular shaped hysteresisfrRotateur de Faraday avec hystérésis rectangulaire2MITSUBISHI GAS CHEMICAL COMPANY, INC.0028763056 MG 03 085-2, Marunouchi 2-chome Chiyoda-KuTokyo, 100JPShirai, Kazushi, Mitsubishi Gas Chem. Co., Inc.Tokyo Lab., 1-1, Nijiuku 6-chomeKatsushika-ku, Tokyo 125JPTakeda, Norio, Mitsubishi Gas Chem. Co., Inc.Tokyo Lab., 1-1, Nijiuku 6-chomeKatsushika-ku, Tokyo 125JPHiramatsu, Kiyonari, Mitsubishi Gas Chem. Co. Inc.Tokyo Lab., 1-1, Nijiuku 6-chomeKatsushika-ku, Tokyo 125JPKUHNEN, WACKER & PARTNER00100051Alois-Steinecker-Strasse 2285354 FreisingDEATBECHDEDKESFRGBGRIEITLILUMCNLPTSE19980401199814

A Faraday rotator is formed of a bismuth-substituted iron garnet single crystal film grown by a liquid phase epitaxial method. The single crystal film is represented by a formula: Tb3-xBixFe5-y-zGayAlzO12 wherein x has the range 1.1 ≦x≦1.5, y+z has the range 0.65≦y+z≦1.2, and z has the range z≦y. The bismuth-substituted rare earth single crystal film is subjected to a magnetization process where the single crystal film is magnetized by an external magnetic field so that the film has a square magnetic hysteresis loop. The external magnetic field has a magnetic field strength of 1,000 Oe or higher and is applied in a direction normal to a surface of the bismuth-substituted rare earth iron garnet single crystal film.